/*
 * Copyright 2019 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.samples.apps.iosched.shared.domain.settings

import androidx.core.os.BuildCompat
import com.google.samples.apps.iosched.model.Theme
import com.google.samples.apps.iosched.model.themeFromStorageKey
import com.google.samples.apps.iosched.shared.data.prefs.PreferenceStorage
import com.google.samples.apps.iosched.shared.domain.UseCase
import javax.inject.Inject

open class GetThemeUseCase @Inject constructor(
    private val preferenceStorage: PreferenceStorage
) : UseCase<Unit, Theme>() {
    override fun execute(parameters: Unit): Theme {
        preferenceStorage.selectedTheme?.let { key ->
            return themeFromStorageKey(key)
        }
        // If we get here, we don't currently have a theme set, so we need to provide a default
        return when {
            BuildCompat.isAtLeastQ() -> Theme.SYSTEM
            else -> Theme.BATTERY_SAVER
        }
    }
}